var precurrent = 1;
var nexcurrent = 1;
$(".news-block .btn-pre").on('click', function() {
    var num = precurrent % 2;
    if (num != 0) {
        $(".news-block .pic-all").animate({
            marginLeft: "-1000px"
        }, 500)
    } else {
        $(".news-block .pic-all").animate({
            marginLeft: "0px"
        }, 500)
    }
    precurrent++
})
$(".news-block .btn-next").on('click', function() {
    var num = nexcurrent % 2;
    if (num != 0) {
        $(".news-block .pic-all").animate({
            marginLeft: "-1000px"
        }, 500)
    } else {
        $(".news-block .pic-all").animate({
            marginLeft: "0px"
        }, 500)
    }
    nexcurrent++
})